The first aspect to consider is the condition of the
mother colony, which has to be healthy and without diseases or bleached (Highsmith 1982). This will maximize the
chances of a coral fragment to become a vigorous coral
nubbin. Fragment size is also critical and should preferably
be deduced from growth kinetics as was outlined in the section on coral quantity. From a kinetic point of view, making small fragments best propagates massive corals, whereas
for branched corals, fragment size is of lower importance.
However, smaller fragments are considered to be more vulnerable and sometimes exhibit higher mortality rates (Heyward & Collins 1985; Soong & Chen 2003; Okuboet al.
2005; Edwards & Gomez 2007), which is due to a higher
sensitivity to wave action (Clark & Edwards 1995) and a
higher susceptibility to fouling (in particular by algae), predation (Edwards & Gomez 2007) and smothering by sedimentation (Soong & Chen 2003). In particular, for
mariculture, where factors such as predation, sedimentation and water movement cannot be controlled, it is beneficial to use larger and more robust fragments. For culture in
aquarium systems, where predation and wave action can be
excluded and where the application of appropriate husbandry techniques can control sedimentation and fouling,
small fragments may be the best starting point. An increasingly popular approach for propagation of corals is to start
withex situculture of small fragments in aquaria, followed